Abstract 281: External Validation Of The Tips65 Score For Predicting Good Neurological Outcome In Out-of-hospital Cardiac Arrest Patients Treated With Extracorporeal Cardiopulmonary Resuscitation

Abstract

Introduction: Estimating prognosis after out-of-hospital cardiac arrest (OHCA) at early timing during resuscitation efforts is important to select appropriate candidates for extracorporeal cardiopulmonary resuscitation (ECPR). The TiPS65 scoring system is a prediction model that can be used for predicting favorable neurological outcome of adult OHCA patients treated with ECPR using the following four variables: time from call to hospital arrival, initial cardiac rhythm on hospital arrival, initial pH value, and age. However, it is not yet externally validated. We aimed to perform the external validation of the TiPS65 score. Methods: This prognostic study used data from the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest registry, a nationwide, multicenter, prospectively registered database including 83 emergency departments in Japan from January 2018 to December 2019. All adult OHCA patients with shockable rhythm who were treated with ECPR were included. The primary outcome was 30-day survival with favorable neurological outcome defined as Cerebral Performance Category 1 or 2. The predicted probability of outcomes in this cohort was calculated according to the formula developed in the original study. The discrimination and calibration performances were investigated with c-statistic and calibration plots, respectively. Results: A total of 590 patients (men: 517 [81.6%], median age [interquartile range]: 60 [50-69] years) were included, and favorable neurological outcome were reported in 64 (10.8%). The c-statistic of the prediction model was 0.752 (95% CI: 0.694-0.81). The mean predicted probabilities were 1.6% (range: 1.6%-1.6%), 4.5% (3.1%-5.9%), 12% (10.1%-13.9%), 26.2% (22.7%-29.7%), and 48.8% (48.8%-48.8%) for a TiPS65 score of 0, 1, 2, 3, and 4, respectively. These scores were generally well-calibrated to the observed outcomes. Conclusions: In our external validation study of the TiPS65 score for OHCA patients treated with ECPR, the score showed good discrimination and calibration performances. This score would be helpful in the decision-making process for patient selection for ECPR after OHCA.